Question

In a certain population, only $0.03$ percent of the people have physical trait X. On the average, it will be necessary to screen how many people to find six percent of them with trait X?

• A. $180$
• B. $200$
• C. $1800$
• D. $20000$

Answer 1

The correct option is D $20000$

$\Rightarrow$ Let out of 100 people, 0.03% of the people are screened.

$\therefore$ $6\%$ of the people are screened out of

$\Rightarrow$ $\frac{100}{0.03}\times 6=20,000$